Alzheimer's brain effects can differ between racial groups
Alzheimer's disease may cause different changes in the brain in African-Americans than in white Americans of European descent, according to a study published in the July 15 online issue of Neurology, the medical journal of the American Academy of Neurology.
“Our study has important clinical implications because it may suggest a need for different types of Alzheimer's prevention and treatments in African-Americans,” study author Lisa L. Barnes, PhD, with Rush University Medical Center in Chicago, said in a statement. “Indeed, current Alzheimer's drugs primarily target specific Alzheimer pathologies in the brain. Given the mixed pattern of disease that we see in African-American brains, it will be important to develop new treatments that target these other common pathologies, particularly for African-Americans.”
The study compared the brains of 41 African-Americans and 81 European-Americans in whom Alzheimer's dementia had been diagnosed. Researchers looked for typical signs of Alzheimer's disease—plaques and tangles—as well as other brain changes that can cause dementia, such as infarcts and Lewy bodies. They also looked at small and large blood vessel disease.
Only about half of the European-Americans had pure Alzheimer's disease pathology, whereas the rest had Alzheimer's disease pathology with either infarcts or Lewy bodies. In contrast, less than 25 percent of the African-Americans had pure Alzheimer's disease pathology. On the other hand, 71 percent of African-Americans had Alzheimer's disease pathology mixed with another type of pathology, compared with 51 percent of European-Americans.
Clinical Alzheimer's disease in African-Americans was much more likely to involve pathologies other than Alzheimer's disease pathology. African-Americans also had more frequent and severe blood vessel disease.